Objective: The incidence of sexual dysfunction due to antidepressant drugs reported in premarketing clinical efficacy trials is often several times lower than in subsequent clinical experiences and independent reports. Although it is commonly believed that the reason for this discrepancy is that the nonleading questions employed in conventional clinical trials underestimate sexual dysfunction while the direct questioning used in independent trials provides more accurate data, few studies have actually compared these 2 methods.

Method: In this study, 119 patients with a DSM-IV-defined major depressive episode (82 women and 37 men) who had been treated with but not responded to a selective serotonin reuptake inhibitor (SSRI; either citalopram or paroxetine) were assessed regarding sexual functioning by means of open-ended questions and direct questioning at baseline (after SSRI treatment only) and after 4 weeks of SSRI treatment plus buspirone or placebo.

Results: More patients reported sexual dysfunction in response to direct questioning (41%) as compared with spontaneous report (6%) (p < .001). Sexual dysfunction correlated with the duration of the depressive episode, but not with age, dose of SSRI, plasma level of SSRI, duration of SSRI treatment, or any measurement of depression. No statistically significant differences regarding the incidence of sexual dysfunction were found between the citalopram and the paroxetine groups.

Conclusion: Open-ended questions are an insufficient tool to estimate sexual dysfunction, and premarketing clinical trials should therefore include basic explicit assessments. The failure to find a correlation between treatment duration and sexual dysfunction adds to the notion that sexual side effects due to SSRIs do not abate over time.